The present invention relates to a dynamic sequencer for sheets of printed paper and more particularly to a dynamic sequencer for sheets of paper printed in two-up and slalom for being used in a files forming machine and comprising an input section for two sheets lying in a flanking relationship with respects to a longitudinal axis and a collecting station for collecting the superposed sheets.
Generally, the files forming machines utilize laser printers, which, for reason of cost and velocity, print the data on continuous forms with perforated edges having the width of two flanked sheets. In fact, the cost of a laser printing for commercial purposes depends on the number of rows and not on their width. The sheets are printed together, as alternated couples, on the moving form and according to the method known as in xe2x80x9ctwo-upxe2x80x9d and xe2x80x9cslalom.xe2x80x9d A sequencer device separates the sheets by means of longitudinal and transversal cuts on the form and superimposes the individual sheets, in sequence, for the formation of the files in the established order.
A sequencer for sheets of paper printed in two-up is known in which the sheets separated from the continuous form are temporarily arrested in front of a conveyor belt disposed perpendicularly to and beneath the cutting station. Two solenoids are simultaneously actuated for pushing the sheets on the conveyor belt. Then, the belt superimposes the sheets, in the sense of the width, against stop elements of another conveyor belt. In view of the intermittent movement of the sheets, a sequencer of this type is relatively time-consuming in the forming of the files. Further, the transversal disposition of the conveyor belt is the cause of an excessive encumbrance of the files forming machine.
A known dynamic sequencer of printed sheets provides to engage the sheets with two deflectors after the separation from the form. The deflectors twist the sheets and upset them on a transversal conveyor belt for the collection of the file. This sequencer is quick but results rather expensive and bulky owing to he catching mechanism necessary to assuring a twisting without jams of the separated sheets. Further the files will result upset, with difficulties fin positioning data reading devices and rotated through 90xc2x0 with respect to the axis of advancing , with difficulties in the operation of a following device.
The principal object of the present invention is therefore to provide a dynamic sequencer for two-up and slalom printed sheets to be used in files forming machines performing a high productivity and resulting of costs and dimensions relatively limited.
This object is achieved by the dynamic sequencer of the above mentioned type, comprising overlapping means for moving the sheets of a file from the input section to the collecting station along two respective trajectories, in which the overlapping means provides a transversal constant trim, and in which the trajectories of the sheets include at least a divergent portion divergent in height from the input section, at least an approaching portion for approaching, in projection, at least a sheet toward another sheet along the longitudinal axis and at least a concurrent portion for causing at least a sheet to be concurrent in height toward the collecting station in a superimposed relationship with another sheet of the file.
The characteristics of the invention will become clear from the following detailed description of a preferred embodiment given purely by way of non-limitative example with the aid of the accompanying drawings wherein: